Glass clear heavy gauge sheet with copolyester

Abstract

The present invention relates to a glass clear heavy gauge sheet with copolyester, having over than 83% of lights transmittance and lower than 5% of Haze, prepared by copolymer wherein polymerized [A] the acid ingredient component (i) terephthalate moiety as major component and (ii) essentially including 2,6-naphthalenedicarboxylate moiety, and (iii) selectively including isophthalate moiety with [B] the glycol component of (i) ethyleneglycol (EG) itself or (ii) the mixture of ethyleneglycol (EG) and 1,4-cyclohexandimethanol (CHDM). A glass clear heavy gauge sheet with copolyester of the present invention is suitable various industrial usages such as glass substitute of automobile, window glass substitute of high building, and transparent soundproof wall.

What is claimed is:  
     
       1. A heavy gauge clear glass sheet composed of copolyester resins having more than 83% of visible light transmittance and lower than 5% of haze, prepared from a copolymer polymerized with an acid component consisting of (i) a terephthalate moiety and a 2,6-naphthalene dicarboxylate moiety or (ii) a terephthalate moiety, a 2,6-naphthalene dicarboxylate moiety and an isophthalate moiety with glycol component comprising (i) ethyleneglycol (EG) itself, or (ii) the mixture of ethyleneglycol (EG) and 1,4-cyclohexandimethanol (CHDM), the aforesaid copolymer being (i) stable firmly so as not to decompose when melted; and (ii) having a high melt viscosity, such that when cooling there is no crystallization to deteriorate transparency, and the resins are of low crystallinity. 
     
     
       2. A heavy gauge clear glass sheet of copolyester resins prepared according to claim  1 , wherein the heat of cooling crystallization (ΔHme) is less than 1.0 J/g. 
     
     
       3. A heavy gauge clear glass sheet of copolyester resins prepared according to claim  1 , wherein the melt viscosity measured in shear rate of 100 sec.-1 at the temperature of 270° C. is from 1700 to 30,000 poise. 
     
     
       4. A heavy gauge clear glass sheet of copolyester prepared according to claim  1 , wherein the melt viscosity measured in shear rate of 1000 sec.-1 at the temperature of 270° C. is 900 to 8,000 poise. 
     
     
       5. A heavy gauge clear glass sheet of copolyester prepared according to claim  1 , wherein the thickness is over 1 mm. 
     
     
       6. A heavy gauge clear glass sheet of copolyester prepared according to claim  1 , wherein the refractive index of visible light is from 1.35 to 1.70. 
     
     
       7. A heavy gauge clear glass sheet of copolyester prepared according to claim  1 , wherein the terephthalate moiety comprises dimethylterephthalate (DMT) or terephthalic acid (TPA). 
     
     
       8. A heavy gauge clear glass sheet of copolyester prepared according to claim  1 , wherein the dicarboxylate moiety is either dimethyl-2,6-naphthalenedicarboxylate (NDC) or 2,6-naphthalenedicarboxyl acid (NDA). 
     
     
       9. A heavy gauge clear glass sheet of copolyester prepared according to claim  1 , wherein the isophthalate moiety is isophthalic acid (IPA) or dimethylisophthalate (DMI). 
     
     
       10. A heavy gauge clear glass sheet of copolyester prepared according to claim  1 , wherein the content of 2,6-napthalenedicarboxylate moiety is less than 20 mol % based upon the total acid component.